html {
  background: #ffffef;
}
#wrapper {
  width: 409px;
  margin: 50px auto;
  text-align: center;
}
#container {
  width: 407px;
  height: 407px;
  display: -ms-grid;
  display: grid;
  -ms-grid-columns: (50px)[8];
  grid-template-columns: repeat(8, 50px);
  -ms-grid-rows: (50px)[8];
  grid-template-rows: repeat(8, 50px);
  grid-gap: 1px;
  background: Khaki;
  border: 1px solid Khaki;
}
.cell {
  background: DarkKhaki; 
  padding: 5px;
  cursor: pointer;
}
.cell.black::before {
  content: "";
  display: block;
  width: 40px; 
  height: 40px; 
  border-radius: 50%; 
  background: #000;
}
.cell.white::before {
  content: "";
  display: block;
  width: 40px; 
  height: 40px; 
  border-radius: 50%; 
  background: #fff;
}
#message {
  padding: 14px;
  color: #444;
}
button {
  width: 50px;
  height:  22px;
  background: #fff;
  border: 1px solid DarkKhaki;
  box-shadow: border-box;
  border-radius: 2px;
  outline: none;
  font-size: 12px;
  color: DarkKhaki;
  cursor: pointer;
}
button:hover {
  opacity: .8;
}
button:active {
  color: Khaki;
  border-color: Khaki;
}
